Organic light emitting display device, head mounted display including the same and method of fabricating the same

ABSTRACT

An organic light emitting display device includes: an insulating layer; first electrodes on the insulating layer and spaced from each other by a gap; an organic light emitting layer on the first electrodes; and a second electrode on the organic light emitting layer, wherein the insulating layer includes a trench between the first electrodes, wherein the organic light emitting layer includes a first stack on the first electrodes, a charge generating layer on the first stack, and a second stack on the charge generating layer, wherein each of the first and second stacks includes a hole transporting layer, at least one emitting material layer and an electron transporting layer, and wherein the first stack has a discontinuous portion in the trench.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority of Korean PatentApplication No. 10-2017-0103687 filed in the Republic of Korea on Aug.16, 2017, which is hereby incorporated by reference in its entirety forall purposes as if fully set forth herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to an organic light emitting displaydevice, and more particularly to an organic light emitting displaydevice, a head mounted display including the organic light emittingdisplay device and a method of fabricating the organic light emittingdisplay device.

Description of the Related Art

As the information age progresses, display devices processing anddisplaying a large amount of information have rapidly advanced.Recently, various display devices such as a liquid crystal display (LCD)device, a plasma display panel (PDP) device and an organic lightemitting display (OLED) device have been utilized.

Among various display devices, the OLED device of an emissive typedevice has advantages of a viewing angle and a contrast ratio ascompared with the LCD device. Since an additional backlight unit is notrequired, the OLED device has a light weight, a thin profile and a lowpower consumption. In addition, the OLED device is driven with a lowdirect current voltage and has a fast response speed. Specifically, theOLED device has a low fabrication cost.

The OLED device includes an anode, a bank layer dividing the anode, ahole transporting layer (HTL) on the anode, an organic light emittinglayer on the HTL, an electron transporting layer (ETL) on the organiclight emitting layer and a cathode on the ETL. When a high level voltageand a low level voltage are applied to the anodes and the cathode,respectively, a hole and an electron move to the organic light emittinglayer through the HTL and the ETL, respectively, and are combined witheach other to emit a light.

Recently, a head mounted display (HMD) including the OLED device hasbeen developed. The HMD may be a glass type monitor for a virtualreality (VR) or an augmented reality (AR) where a focus is formed at aclose distance to an eye of a user. The user may wear the HMD as a glassor a helmet. A small sized OLED device of a high resolution may beapplied to the HMD. The small sized OLED device of a high resolution maybe an organic light emitting diode on silicon (OLEDoS) through asemiconductor process for a wafer. An anode is formed on an insulatinglayer covering a transistor formed on a wafer, and a current flowsthrough an organic light emitting layer on the anode to cause a sideleakage current. In addition, since the organic light emitting layer isnot uniformly formed at an edge of the anode due to a step differencebetween the anode and the insulating layer, the anode may be connectedto the cathode or a charge generating layer of the organic lightemitting layer.

SUMMARY OF THE INVENTION

Accordingly, the present disclosure is directed to an organic lightemitting display device, a head mounted display including the same and amethod of fabricating the same that substantially obviate one or more ofproblems due to limitations and disadvantages of the prior art.

In accordance with the present disclosure, as embodied and broadlydescribed herein, the present disclosure provides an organic lightemitting display device where a shortage of an anode to a cathode or acharge generating layer of an organic light emitting layer and a sideleakage current are prevented, a head mounted display including theorganic light emitting display device and a method of fabricating theorganic light emitting display device.

In another aspect, the present disclosure provides an organic lightemitting display device including: an insulating layer; first electrodesdisposed on the insulating layer and spaced from each other by a gap; anorganic light emitting layer on the first electrodes; and a secondelectrode on the organic light emitting layer, wherein the insulatinglayer includes a trench in the gap between the first electrodes, whereinthe organic light emitting layer includes a first stack on the firstelectrodes, a charge generating layer on the first stack, and a secondstack on the charge generating layer, wherein each of the first andsecond stacks includes a hole transporting layer, at least one emittingmaterial layer and an electron transporting layer, and wherein the firststack has a discontinuous portion in the trench.

In another aspect, the present disclosure provides a head mounteddisplay including: a display case; a left eye lens and a right eye lensin the display case; at least one organic light emitting display deviceproviding at least one image to the left eye lens and the right eyelens; and a head band connected to the display case, wherein the atleast one organic light emitting display device includes: an insulatinglayer; first electrodes disposed on the insulating layer and spaced fromeach other by a gap; an organic light emitting layer on the firstelectrodes; and a second electrode on the organic light emitting layer,wherein the insulating layer includes a trench in the gap between thefirst electrodes, wherein the organic light emitting layer includes afirst stack on the first electrodes, a charge generating layer on thefirst stack, and a second stack on the charge generating layer, whereineach of the first and second stacks includes a hole transporting layer,at least one emitting material layer and an electron transporting layer,and wherein the first stack has a discontinuous portion in the trench.

In another aspect, the present disclosure provides a method offabricating an organic light emitting display device including: formingan insulating layer on a substrate; forming first electrodes on theinsulating layer, the first electrodes spaced from each other by a gap;forming an organic light emitting layer on the first electrodes; andforming a second electrode on the organic light emitting layer, whereinthe insulating layer includes a trench in the gap between the firstelectrodes, wherein the organic light emitting layer includes a firststack on the first electrodes, a charge generating layer on the firststack, and a second stack on the charge generating layer, wherein eachof the first and second stacks includes a hole transporting layer, atleast one emitting material layer and an electron transporting layer,and wherein the first stack has a discontinuous portion in the trench.

In another aspect, the present disclosure provides an organic lightemitting display device including: a first sub-pixel including a firstelectrode of the first sub-pixel covering an insulating layer of thefirst sub-pixel; a second sub-pixel including a first electrode of thesecond sub-pixel covering an insulating layer of the second sub-pixel;and a trench between the first sub-pixel and the second sub-pixel thatextends down through at least part of an insulating layer between thefirst sub-pixel and the second sub-pixel, wherein the insulating layerof the first sub-pixel, the insulating layer of the second sub-pixel,and the insulating layer between the first sub-pixel and the secondsub-pixel are part of a same layer, wherein the organic light emittinglayer includes a first stack on the first electrodes, a chargegenerating layer on the first stack, and a second stack on the chargegenerating layer, wherein each of the first and second stacks includes ahole transporting layer, at least one emitting material layer and anelectron transporting layer, and wherein the first stack has adiscontinuous portion in the trench.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the embodiments as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate embodiments and together with thedescription serve to explain the principles of the disclosure. In thedrawings:

FIG. 1 is a perspective view showing an organic light emitting displaydevice according to one or more embodiments of the present disclosure.

FIG. 2 is an example cross-sectional view taken along a line I-I′ ofFIG. 1.

FIGS. 3A and 3B are magnified views of a portion A of FIG. 2 accordingto different embodiments of the present disclosure.

FIG. 4 is a flow chart showing a method of fabricating an organic lightemitting display device according to a first embodiment of the presentdisclosure.

FIGS. 5A, 5B, 5C, 5D, 5E, 5F, 5G and 5H are cross-sectional viewsshowing a method of fabricating an organic light emitting display deviceaccording to a first embodiment of the present disclosure.

FIG. 6 is a cross-sectional view showing an organic light emittingdisplay device according to another embodiment of the presentdisclosure.

FIGS. 7A, 7B, 7C, and 7D are cross-sectional views showing a method offabricating an organic light emitting display device according to asecond embodiment of the present disclosure.

FIGS. 8A, 8B, 8C, 8D, and 8E are cross-sectional views showing a methodof fabricating an organic light emitting display device according to athird embodiment of the present disclosure.

FIGS. 9A and 9B are cross-sectional views showing a method offabricating an organic light emitting display device according to afourth embodiment of the present disclosure.

FIG. 10 is photographs showing experimental results of the sixth trenchof an organic light emitting display device according to one of first tofourth embodiments of the present disclosure.

FIG. 11 is a graph showing experimental results of the sixth trench ofan organic light emitting display device according to one of first tofourth embodiments of the present disclosure.

FIG. 12 is a graph showing simulation results of the sixth trench of anorganic light emitting display device according to one of first tofourth embodiments of the present disclosure.

FIG. 13 is a plan view showing an organic light emitting display deviceaccording to one of first to fourth embodiments of the presentdisclosure.

FIGS. 14A and 14B are a perspective view and a plan view showing a headmounted display including an organic light emitting display deviceaccording to one of first to fourth embodiments of the presentdisclosure.

FIG. 15 is a plan view showing a head mounted display including anorganic light emitting display device according to one of first tofourth embodiments of the present disclosure.

FIG. 16 is a cross-sectional view showing a head mounted displayincluding an organic light emitting display device according to one offirst to fourth embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, some embodiments of the present disclosure will bedescribed in detail with reference to the accompanying illustrativedrawings. In designating elements of the drawings by reference numerals,the same elements will be designated by the same reference numeralsalthough they are shown in different drawings. Further, in the followingdescription of the present disclosure, a detailed description of knownfunctions and configurations incorporated herein will be omitted when itmay make the subject matter of the present disclosure rather unclear.

Since a shape, a size, a ratio, an angle and a number shown in drawingsfor illustrating embodiments of the present disclosure are exemplary,the present disclosure will not be limited to contents of the drawings.

In the case that it is described that a certain structural element“include,” “have” and “is composed of,” another elements may be addedexcept for the case where “only” is used. An element expressed as asingularity includes a plurality except for the case having a specificdescription.

When an element is construed, the element includes an error range evenwithout a specific description.

When a position relation of two parts is illustrated with “on,” “over,”“under” and “side,” at least one part may be disposed between the twoparts except for the case using “straightly” and “directly.”

When a time relation is illustrated with “after,” “subsequently,” “next”and “before,” a case which is not sequential may be included except forthe case using “straightly” and “directly.”

Although a first and a second may be used for illustrating variouselements, the elements are not limited by the word. The word is used fordistinguish one element from the other elements. Accordingly, a firstelement may be a second element within a scope of the spirit of thepresent disclosure hereinafter.

A relation of “an X axis direction,” “a Y axis direction” and “a Z axisdirection” is not interpreted as a geometrical vertical relation, therelation may be interpreted to have a wide directionality within a rangewhere the present disclosure operates functionally.

A word of “at least one” should be construed to include all combinationssuggested from at least one relating items. For example, “at least oneof a first item, a second item and a third item” may mean allcombinations suggested from two or more of the first, second and thirditems as well as each of the first, second and third items.

Characteristics of various embodiments of the present disclosure may becombined or united partially or wholly and may be technicallycommunicated and driven. The embodiments may be implementedindependently or together.

FIG. 1 is a perspective view showing an organic light emitting displaydevice according to one or more embodiments of the present disclosure.Although an organic light emitting display (OLED) device is illustratedas an organic light emitting diode on silicon (OLEDoS) where an organiclight emitting diode is formed on a wafer through a semiconductorprocess in FIG. 1, the present disclosure is not limited.

In FIG. 1, an organic light emitting display (OLED) device 100 accordingto a first embodiment of the present disclosure includes a wafersubstrate 110, first electrodes 121, an organic light emitting layer130, a second electrode 140 and an encapsulation layer 180.

The wafer substrate 110 may be a silicon wafer substrate formed using asemiconductor process. The wafer substrate 110 may include a gate line,a data line and a transistor. The gate line and the data line may bedisposed to cross each other. The gate line may be connected to a gatedriving unit to receive a gate signal. The data line may be connected toa data driving unit to receive a data signal.

A region where the first electrodes 121, the organic light emittinglayer 130 and the second electrode 140 are sequentially formed may bedefined as a pixel or sub-pixel. Hereinafter, what is referred to as“pixel” or “pixels” can also be interpreted as “sub-pixel” or“sub-pixels”. For example, the first electrodes 121 are spaced apartfrom each other by a gap distance equal to or smaller than about 0.7 μm.Since the first electrodes 121 are spaced apart from each other on thewafer substrate 110, the pixel may be divided by the first electrodes121. N transistors (N is a positive integer) may be disposed in thepixel, and a voltage is supplied to the first electrode 121 according tothe data signal of the data line when the gate signal of the gate lineis applied to the N transistors.

The organic light emitting layer 130 may be formed to cover the wafersubstrate 110 and the first electrode 121. The organic light emittinglayer 130 may be a common layer formed over the whole pixels commonly.

The second electrode 140 may be formed to cover the organic lightemitting layer 130. The second electrode 140 may be a common layerformed over the whole pixels commonly.

The encapsulation layer 180 may be formed to cover the second electrode140. The encapsulation layer 180 may function to prevent penetration ofan oxygen and a moisture to the organic light emitting layer 130 and thesecond electrode 140.

FIG. 2 is an example cross-sectional view taken along a line I-I′ ofFIG. 1, and FIGS. 3A and 3B are magnified views of a portion A of FIG. 2according to different embodiments of the present disclosure. Forpurposes of simplicity, FIG. 2 (and FIGS. 5H, 6, and 7D) depict theorganic light emitting layer 130 in the trench T as being continuous.However, in embodiments of the present disclosure, at least one of thelayers 130 a and/or 130 b in the organic light emitting layer 130 in thetrench T is discontinuous, as shown in the magnified views of FIGS. 3Aand 3B, respectively.

In FIGS. 2, 3A and 3B, the transistors 111 are formed on the wafersubstrate 110. Each of the transistors 111 includes an active layer 111a, a gate electrode 111 b, a source electrode 111 c and a drainelectrode 111 d. Although each of the transistors 111 has a top gatetype where the gate electrode 111 b is formed on the active layer 111 ain FIG. 2, the embodiment is not limited to FIG. 2. Each of thetransistors 111 may have a bottom gate type where the gate electrode 111b is formed under the active layer 111 a or a double gate type where thegate electrode 111 b is formed on and under the active layer 111 a.

The active layer 111 a is formed on the wafer substrate 110. The activelayer 111 a may include a semiconductor material of a silicon group or asemiconductor material of an oxide group. A gate insulating layer 112 isformed on the active layer 111 a. The gate insulating layer 112 may havea single-layered structure or a multiple-layered structure of aninorganic material such as silicon oxide (SiOx) and silicon nitride(SiNx). The gate electrode 111 b is formed on the gate insulating layer112.

The source electrode 111 c is connected to the active layer 111 athrough a first trench 111 e, and the drain electrode 111 d is connectedto the active layer 111 a through a second trench 111 f. The activelayer 111 a, the gate electrode 111 b, the source electrode 111 c andthe drain electrode 111 d are insulated from each other by a firstinsulating layer 113. The first insulating layer 113 may have asingle-layered structure or a multiple-layered structure of an inorganicmaterial such as silicon oxide (SiOx) and silicon nitride (SiNx).

A first metal layer 114 a and a second metal layer 115 a are formed onthe first insulating layer 113. The first metal layer 114 a is connectedto the drain electrode 111 d through a third trench 114 b, and thesecond metal layer 115 a is connected to the first metal layer 114 athrough a fourth trench 115 b. The first and second metal layers 114 aand 115 a are insulated by a second insulating layer 117. The secondinsulating layer 117 may have a single-layered structure or amultiple-layered structure of an inorganic material such as siliconoxide (SiOx) and silicon nitride (SiNx). The first metal layer 114 a,the second metal layer 115 a and the second insulating layer 117 may beomitted.

First electrodes 121 are formed on the second insulating layer 117. Eachof the first electrodes 121 is connected to the second metal layer 115 athrough a fifth trench 116. The first electrodes 121 may include atransparent conductive oxide (TCO) such as indium tin oxide (ITO) andindium zinc oxide (IZO).

The OLED device 100 exemplarily has a top emission type where a light isemitted from the organic light emitting layer 130 to an upper portion. Areflecting electrode 122 may be disposed under each of the firstelectrodes 121 to reflect a light emitted from the organic lightemitting layer 130 to a lower portion. The reflecting electrode 122 mayinclude a metallic material having a relatively high reflectance such assilver (Ag).

A buffer electrode 123 may be disposed under the reflecting electrode122. The buffer electrode 123 may have a double-layered structure oftitanium (Ti) and titanium nitride (TiN). The buffer electrode 123 maybe omitted.

The first electrodes 121, the reflecting electrode 122 and the bufferelectrode 123 may have a vertical structure where a side surface of thefirst electrodes 121, the reflecting electrode 122 and the bufferelectrode 123 has a first angle θ1 of about 90 degree with a top surfaceof the second insulating layer 117.

To planarize a step difference due to the first electrodes 121, thereflecting electrode 122 and the buffer electrode 123, a planarizinglayer 150 may be formed between the first electrodes 121. Theplanarizing layer 150 may include a sixth trench T penetrating theplanarizing layer 150 and the second insulating layer 117 may bepartially removed to correspond to the sixth trench T. The planarizinglayer 150 may cover an edge portion of the first electrode 121 in afirst region A1 to prevent a shortage between the first electrode 121and the organic light emitting layer 130 and may be formed on the secondinsulating layer 117 in a third region A3 to adjust a width of the sixthtrench T.

The organic light emitting layer 130 is formed on the first electrodes121 and the planarizing layer 150. The organic light emitting layer 130may include at least one of a hole injecting layer (HIL), a holetransporting layer (HTL), emitting material layer (EML), an electrontransporting layer (ETL) and an electron injecting layer (EIL). Whenvoltages are applied to the first electrode 121 and the second electrode140, a hole moves to the emitting material layer through the HIL and theHTL and an electron moves to the emitting material layer through the EILand the ETL. The hole and the electron are combined with each other toemit a light.

The organic light emitting layer 130 may be a white emitting layer toemit a white-colored light. The organic light emitting layer 130 may bea common layer formed over the whole pixels commonly.

The organic light emitting layer 130 may have a tandem structureincluding at least two stacks. For example, the organic light emittinglayer 130 may include a first stack 130 a, a charge generating layer 130b and a second stack 130 c. Each of the at least two stacks may includea hole transporting layer, at least one emitting material layer and anelectron transporting layer. For example, a first stack may be formed ona first electrode, a charge generating layer may be formed on the firststack, and a second stack may be formed on the charge generating layer.In addition, a second charge generating layer may be formed on thesecond stack, and an additional stack may be formed on the second chargegenerating layer.

The charge generating layer may be formed between the stacks. The chargegenerating layer may include an N type charge generating layer adjacentto a lower stack and a P type charge generating layer over the N typecharge generating layer adjacent to an upper stack. The N type chargegenerating layer injects an electron to the lower stack, and the P typecharge generating layer injects a hole to the upper stack. The N typecharge generating layer may include an organic layer doped with analkali metal such as lithium (Li), sodium (Na), potassium (K) and cesium(Cs) or an alkaline earth metal such as magnesium (Mg), strontium (Sr),barium (Ba) and radium (Ra). The P type charge generating layer mayinclude an organic material having a hole transporting ability dopedwith a dopant.

The organic light emitting layer 130 may be formed through a depositionprocess or a soluble process. For example, the organic light emittinglayer 130 may be formed through an evaporation method of the depositionprocess. The film formed through an evaporation method may have a poorstep coverage property. When the planarizing layer 150 is not disposedbetween the first electrodes 121, the organic light emitting layer 130may have a relatively small thickness at a step difference region overthe first electrode 121 (i.e., a top edge region of the first electrode121). Since a distance between the step difference region of the firstelectrodes 121 and the second electrode 140 is reduced, a strongelectric field is generated between the first and second electrodes 121and 140 at the step difference region. As a result, abnormal emission ordeterioration of the organic light emitting layer 130 may be acceleratedand a shortage between the first electrodes 121 and the chargegenerating layer of the organic light emitting layer 130 or between thefirst electrodes and the second electrode 140 may occur due to thestrong electric field and electrons concentrated on the step differenceregion of the first electrode 121. A step coverage means a capability ofa film to cover a step difference without a cut.

In the first embodiment of the present disclosure, since the planarizinglayer 150 filling the step difference of the second insulating layer 117and the first electrode 121 and covering the step difference region ofthe first electrodes 121 is formed between the first electrodes 121, thestep difference of the first electrode 121 may be mitigated. As aresult, abnormal emission or deterioration of the organic light emittinglayer 130 may be prevented and a shortage between the first electrodes121 and the charge generating layer of the organic light emitting layer130 or between the first electrodes 121 and the second electrode 140 inthe step difference region between the second insulating layer 117 andthe first electrode 121 and over the first electrode 121 may beprevented. Since the planarizing layer 150 is formed to cover the edgeportion of the first electrode 121 in the first region A1, a shortagebetween the first electrode 121 and the organic light emitting layer 130may be prevented. The planarizing layer 150 covering the edge portion ofthe first electrode 121 may define an emitting region of a correspondingpixel. The planarizing layer 150 covering the edge portion of the firstelectrode 121 may prevent injection of charge from the first electrode121 to a portion of the organic light emitting layer 130 covering theplanarizing layer such that it does not emit light. The planarizinglayer 150 contacting the edge portion of the first electrode 121 in thefirst region A1 may have a width equal to or greater than about 0.1 μm.Specifically, as in FIG. 3B, a width of the sixth trench T of theplanarizing layer 150 may be adjusted by forming the planarizing layer150 on the second insulating layer 117 in the third region A3.

Since the organic light emitting layer 130 has a poor step coverageproperty, a thickness of the organic light emitting layer 130 on asidewall of the sixth trench T may be smaller than a thickness on abottom surface of the sixth trench T as in FIGS. 3A and 3B. The sixthtrench T may be divided into two parts in the planarizing layer 150 andthe second insulating layer 117. At least one of the first stack 130 aand the charge generating layer 130 b of the organic light emittinglayer 130 may be formed to have a cut portion (e.g., discontinuousportion) at a position where the sidewall surface and the bottom surfaceof the sixth trench T meet to increase a resistance of the organic lightemitting layer 130. As a result, an influence on an adjacent pixel dueto a leakage current through the organic light emitting layer 130 may beminimized. For example, transmission of the leakage current may beeffectively prevented by the cut portion of the charge generating layer.

In the first embodiment of the present disclosure, since the sixthtrench T is formed in the planarizing layer 150 and the secondinsulating layer 117, a path of the leakage current through the organiclight emitting layer 130 between the adjacent pixels may be elongated ascompared with an OLED device without the sixth trench T. In addition,since the thickness of the organic light emitting layer 130 on thesidewall surface of the sixth trench T is smaller than the thickness ofthe organic light emitting layer 130 on the bottom surface of the sixthtrench T, the resistance of the organic light emitting layer 130 mayincrease and an influence on the adjacent pixel due to a leakage currentthrough the organic light emitting layer 130 may be minimized. Forexample, the sixth trench T may have a width equal to or smaller thanabout 0.17 μm and a depth equal to or greater than about 0.5 μm.

The second electrode 140 is disposed on the organic light emitting layer130. The second electrode 140 may be a common layer formed over thewhole pixels commonly. The second electrode 140 may include atransparent conductive material such as indium tin oxide (ITO) andindium zinc oxide (IZO) or a semi-transmissive conductive material suchas magnesium (Mg), silver (Ag) and alloy of magnesium and silver.

When the second electrode 140 includes a semi-transmissive conductivematerial, a micro cavity effect may be obtained. The second electrode140 may be formed through a physical vapor deposition (PVD) method suchas a sputtering. Since a film formed through a PVD method has anexcellent step coverage, the second electrode 140 may have a uniformthickness as compared with the organic light emitting layer 130 evenwith the sixth trench T.

A sealing layer 160 is formed on the second electrode 140. The sealinglayer 160 may prevent penetration of an oxygen or a moisture to theorganic light emitting layer 130 and the second electrode 140. Forexample, the sealing layer 160 may include at least one inorganic layerand at least one organic layer.

Color filters 171 and 172 are disposed on the sealing layer 160 tocorrespond to the pixels P. For example, a red color filter may bedisposed to correspond to a red pixel, a green color filter may bedisposed to correspond to a green pixel, and a blue color filter may bedisposed to correspond to a blue pixel.

An overcoat layer may be formed on the color filters 171 and 172 toplanarize a step difference due to the color filters 171 and 172. Anencapsulation film 180 may be formed on the color filters 171 and 172.

FIG. 4 is a flow chart showing a method of fabricating an organic lightemitting display device according to a first embodiment of the presentdisclosure, FIGS. 5A to 5H are cross-sectional views showing a method offabricating an organic light emitting display device according to afirst embodiment of the present disclosure, and FIG. 6 is across-sectional view showing an organic light emitting display deviceaccording to another embodiment of the present disclosure. FIGS. 5A to5H correspond to a line I-I′ of FIG. 1, and FIG. 6 corresponds to FIG.5H. For purposes of simplicity, FIGS. 5H and 6 depict the organic lightemitting layer 130 in the trench T as being continuous. However, inembodiments of the present disclosure, at least one of the layers 130 aand/or 130 b in the organic light emitting layer 130 in the trench T isdiscontinuous, as shown in the magnified views of FIGS. 3A and 3B,respectively.

In FIGS. 4 and 5A, the transistors 111 are formed on the wafer substrate110 (S101). The active layer 111 a of each of the transistors 111 isformed on the wafer substrate 110. The active layer 111 a may include asemiconductor material of a silicon group or a semiconductor material ofan oxide group.

The gate insulating layer 112 is formed on the active layer 111 a. Thegate insulating layer 112 may include a single-layered structure or amultiple-layered structure of an inorganic material such as siliconoxide (SiOx) and silicon nitride (SiNx).

The gate electrode 111 b is formed on the gate insulating layer 112. Thefirst insulating layer 113 is formed on the active layer 111 a and thegate electrode 111 b. The first insulating layer 113 may include asingle-layered structure or a multiple-layered structure of an inorganicmaterial such as silicon oxide (SiOx) and silicon nitride (SiNx).

The first and second trenches 111 e and 111 f exposing the active layer111 a are formed in the first insulating layer 113. The source electrode111 c and the drain electrode 111 d are formed on the first insulatinglayer 113. The source electrode 111 c is connected to the active layer111 a through the first trench 111 e, and the drain electrode 111 d isconnected to the active layer 111 a through the second trench 111 f.

The first insulating layer 113 is further formed on the source electrode111 c and the drain electrode 111 d. The third trench 114 b exposing thedrain electrode 111 d is formed in the first insulating layer 113. Thefirst metal layer 114 a is formed on the first insulating layer 113. Thefirst metal layer 114 a is connected to the drain electrode 111 dthrough the third trench 114 b.

The second insulating layer 117 is formed on the first metal layer 114a. The second insulating layer 117 may include a single-layeredstructure or a multiple-layered structure of an inorganic material suchas silicon oxide (SiOx) and silicon nitride (SiNx).

The fourth trench 115 b exposing the first metal layer 114 a is formedin the second insulating layer 117. The second metal layer 115 a isformed on the second insulating layer 117. The second metal layer 115 ais connected to the first metal layer 114 a through the fourth trench115 b.

The second insulating layer 117 is further formed on the second metallayer 115 a. The fifth trench 116 exposing the second metal layer 115 ais formed in the second insulating layer 117.

In FIGS. 4 and 5B, the first electrodes 121 are formed on the secondinsulating layer 117 (S102). The buffer metal layer 123 a, thereflecting metal layer 122 a and a first metal layer 121 a aresequentially formed on the second insulating layer 117. The buffer metallayer 123 a may have a double-layered structure of titanium (Ti) andtitanium nitride (TiN). The reflecting metal layer 122 a may include ametallic material having a relatively high reflectance such as silver(Ag). The first metal layer 121 a may include a transparent conductiveoxide (TCO) such as indium tin oxide (ITO) and indium zinc oxide (IZO).

A photoresist pattern is formed on the first metal layer 121 a, thereflecting metal layer 122 a and the buffer metal layer 123 a. Thephotoresist pattern may be disposed in the pixels P.

In FIGS. 4 and 5C, the first electrodes 121, the reflecting electrodes122 and the buffer electrodes 123 are formed by dry-etching the firstmetal layer 121 a, the reflecting metal layer 122 a and the buffer metallayer 123 a outside the photoresist pattern. Next, the photoresistpattern is removed.

In FIGS. 4 and 5D, the planarizing layer 150 is formed on the firstelectrodes 121 (S103). The planarizing layer 150 fills a space betweenthe first electrodes 121. A filling material layer 150 a is formed onthe second insulating layer 117 and the first electrode 121. Forexample, the filling material layer 150 a may include one of acrylicresin, epoxy resin, phenolic resin, polyamide resin and polyimide resin.

In FIGS. 4 and 5E, the filling material layer 150 a is patterned througha photolithographic process using a photo mask PM to form theplanarizing layer 150. A step of forming a photoresist layer and a stepof forming a photoresist pattern corresponding to a mask pattern areomitted in FIG. 5E.

In FIGS. 4 and 5F, the filling material layer 150 a may be patternedthrough a direct exposure and a direct etching without the photoresistpattern according to a material property of the filling material layer150 a. An etching material which can etch the filling material layer 150a and cannot etch the first electrodes 121 may be selected for the stepof etching the filling material layer 150 a. The planarizing layer 150may include a second region A2 covering a side surface of the firstelectrodes 121. The planarizing layer 150 may further include at leastone of a first region A1 covering an edge top surface of the firstelectrodes 121 and a third region A3 covering the second insulatinglayer 117. The third region A3 may have a width greater than the secondregion A2. The planarizing layer 150 may be spaced apart from each otherby the sixth trench T (S104).

In FIGS. 4 and 5G, the second insulating layer 117 is etched using theplanarizing layer 150 as an etching mask. Since an additional mask isnot required, a fabrication process is simplified. In addition, sincethe fabrication deviation is reduced, the defective proportion isreduced and the fabrication cost is reduced. An etching material whichcan etch the second insulating layer 117 and cannot etch the planarizinglayer 150 and the first electrodes 121 may be selected. For example, anetching solution for the second insulating layer 117 may be differentfrom an etching solution for the filling material layer 150 a or thephotoresist pattern of the filling material layer 150 a. The sixthtrench T is formed in the second insulating layer 117 using theplanarizing layer 150 as an etching mask. The etching step for thesecond insulating layer 117 may be combined with the etching step forthe filling material layer 150 a, and an etching material which can etchthe second insulating layer 117 and the planarizing layer 150 and cannotetch the first electrode 121 may be used for the combined step. Theetching material may have different etch rates for the second insulatinglayer 117 and the planarizing layer 150 and have a relatively high etchrate for the second insulating layer 117. Since the sixth trench T isformed using the planarizing layer 150 as an etching mask, a lower edgeof the planarizing layer 150 may coincide with an upper edge of thesixth trench T in the second insulating layer 117. The planarizing layer150 and the second insulating layer 117 may include the sixth trench Tcommonly (S105).

In FIGS. 4 and 5H, the organic light emitting layer 130, the secondelectrode 140 and the sealing layer 160 are sequentially formed on theplanarizing layer 150 having the sixth trench T (S106).

The organic light emitting layer 130 is formed on the first electrodes121 and the planarizing layer 150. The organic light emitting layer 130may be formed through a deposition process or a soluble process. Whenthe organic light emitting layer 130 is formed through a depositionprocess, the organic light emitting layer 130 may be formed using anevaporation method.

The organic light emitting layer 130 may be a white emitting layer toemit a white-colored light. The organic light emitting layer 130 may bea common layer formed over the whole pixels commonly.

When the organic light emitting layer 130 is a white emitting layer, theorganic light emitting layer 130 may have a tandem structure includingat least two stacks. Each of the at least two stacks may include a holetransporting layer, at least one emitting material layer and an electrontransporting layer.

The charge generating layer may be formed between the stacks. The chargegenerating layer may include an N type charge generating layer adjacentto a lower stack and a P type charge generating layer over the N typecharge generating layer adjacent to an upper stack. The N type chargegenerating layer injects an electron to the lower stack, and the P typecharge generating layer injects a hole to the upper stack. The N typecharge generating layer may include an organic layer doped with analkali metal such as lithium (Li), sodium (Na), potassium (K) and cesium(Cs) or an alkaline earth metal such as magnesium (Mg), strontium (Sr),barium (Ba) and radium (Ra). The P type charge generating layer mayinclude an organic material having a hole transporting ability dopedwith a dopant.

The organic light emitting layer 130 formed through an evaporationmethod may have a poor step coverage property. As a result, a thicknessof the organic light emitting layer 130 on the sidewall surface of thesixth trench T may be smaller than a thickness of the organic lightemitting layer 130 on the bottom surface of the sixth trench T. Inaddition, at least one of a stack and a charge generating layer of theorganic light emitting layer 130 may be formed to have a cut portion ata position where the sidewall surface and the bottom surface of thesixth trench T meet to increase a resistance of the organic lightemitting layer 130. As a result, an influence on an adjacent pixel dueto a leakage current through the organic light emitting layer 130 may beminimized.

The second stack 130 c of the organic light emitting layer 130 mayplanarize the unevenness of the charge generating layer 130 b of theorganic light emitting layer 130 corresponding to the sixth trench T tohave a flat top surface in FIG. 5H. In FIG. 6, the second stack 130 c ofthe organic light emitting layer 130 may not planarize the unevenness ofthe charge generating layer 130 b of the organic light emitting layer130 corresponding to the sixth trench T to have an uneven top surface.

The second electrode 140 is formed on the organic light emitting layer130. The second electrode 140 may be a common layer formed over thewhole pixels commonly. The second electrode 140 may include atransparent conductive oxide (TCO) such as indium tin oxide (ITO) andindium zinc oxide (IZO) or a semi-transmissive conductive material suchas magnesium (Mg), silver (Ag) and alloy of magnesium and silver. Whenthe second electrode 140 includes a semi-transmissive conductivematerial, a micro cavity effect may be obtained.

The second electrode 140 may be formed through a physical vapordeposition (PVD) method such as a sputtering. Since a film formedthrough a PVD method has an excellent step coverage, the secondelectrode 140 may have a uniform thickness as compared with the organiclight emitting layer 130 even with the sixth trench T.

The sealing layer 160 is formed on the second electrode 140. The sealinglayer 160 may prevent penetration of an oxygen or a moisture to theorganic light emitting layer 130 and the second electrode 140. Forexample, the sealing layer 160 may include at least one inorganic layerand at least one organic layer.

The color filters 171 and 172 are formed on the sealing layer 160(S107). The color filters 171 and 172 correspond to the pixels. Forexample, a red color filter may be disposed to correspond to a redpixel, a green color filter may be disposed to correspond to a greenpixel, and a blue color filter may be disposed to correspond to a bluepixel. An overcoat layer may be formed on the color filters 171 and 172to planarize a step difference due to the color filters 171 and 172. Theencapsulation film 180 may be attached to the color filters 171 and 172.

FIGS. 7A to 7D are cross-sectional views showing a method of fabricatingan organic light emitting display device according to a secondembodiment of the present disclosure. FIGS. 7A to 7D correspond to aline I-I′ of FIG. 1. For purposes of simplicity, FIG. 7D depicts theorganic light emitting layer 130 in the trench T as being continuous.However, in embodiments of the present disclosure, at least one of thelayers 130 a and/or 130 b in the organic light emitting layer 130 in thetrench T is discontinuous, as shown in the magnified views of FIGS. 3Aand 3B, respectively.

Steps of forming the transistors 111, the first and second metal layers114 a and 115 a, the first electrodes 121 and the filling material layer150 a of the second embodiment are the same as the steps of FIGS. 5A to5D of the first embodiment.

In FIG. 7A, the filling material layer 150 a is patterned through aphotolithographic process using a photo mask PM including threetransmittances to form a tail shape at a contact portion of theplanarizing layer 150 and the second insulating layer 117. Theplanarizing layer 150 may include the first region A1 covering the edgetop surface of the first electrodes 121, the second region A2 coveringthe side surface of the first electrodes 121 and the third region A3contacting the second insulating layer 117 and connected to the secondregion A2. The width of the third region A3 may be greater than thewidth of the second region A2. The width of the sixth trench T may beminutely adjusted by forming the third region A3 with a greater width.Since the mask pattern has different transmittances, the second andthird regions A2 and A3 may be formed to have different thicknesses.

A step of forming a photoresist layer and a step of forming aphotoresist pattern corresponding to a mask pattern are omitted in FIG.7A. The filling material layer 150 a may be patterned through a directexposure and a direct etching without the photoresist pattern accordingto a material property of the filling material layer 150 a. An etchingmaterial which can etch the filling material layer 150 a and cannot etchthe first electrodes 121 may be selected for the step of etching theplanarizing layer 150 a. The planarizing layer 150 may include a secondregion A2 covering a side surface of the first electrodes 121. Theplanarizing layer 150 may further include at least one of a first regionA1 covering an edge top surface of the first electrodes 121 and a thirdregion A3 covering the second insulating layer 117. The third region A3may have a width greater than the second region A2. The planarizinglayer 150 may be spaced apart from each other by the sixth trench T.

In FIG. 7B, the filling material layer 150 a is etched to form theplanarizing layer 150 similarly to FIG. 5G.

In FIG. 7C, the sixth trench T is formed in the second insulating layer117 using the planarizing layer 150 as an etching mask similarly to FIG.5H.

In FIG. 7D, the organic light emitting layer 130, the second electrode140, the sealing layer 160, the color filters 171 and 172 and theencapsulation layer 180 are sequentially formed on the planarizing layer150 having the sixth trench T similarly to FIGS. 5H and 6. The organiclight emitting layer 130 has a step difference due to the sixth trench Tand the third region A3 of the planarizing layer 150.

At least one of a stack and a charge generating layer of the organiclight emitting layer 130 may be formed to have a cut portion at aposition where the sidewall surface and the bottom surface of the sixthtrench T meet to increase a resistance of the organic light emittinglayer 130. As a result, an influence on an adjacent pixel due to aleakage current through the organic light emitting layer 130 may beminimized.

FIGS. 8A to 8E are cross-sectional views showing a method of fabricatingan organic light emitting display device according to a third embodimentof the present disclosure. FIGS. 8A to 8E correspond to a line I-I′ ofFIG. 1.

Steps of forming the transistors 111, the first and second metal layers114 a and 115 a, the first electrodes 121 and the filling material layer150 a of the third embodiment are the same as the steps of FIGS. 5A to5D of the first embodiment.

In FIG. 8A, the filling material layer 150 a is formed according to astep difference of the first electrodes 121 and the second insulatinglayer 117. Although the filling material layer 150 a on the firstelectrodes 121 and the filling material layer 150 a on the secondinsulating layer 117 may be patterned through one etching step as inFIGS. 5F and 7B, the filling material layer 150 a on the firstelectrodes 121 and the filling material layer 150 a on the secondinsulating layer 117 may be patterned using different photo masks.

In FIG. 8B, a first photo mask PM1 is disposed over the filling materiallayer 150 a. The first photo mask PM1 may have a mask patterncorresponding to the first electrodes 121.

In FIG. 8C, the filling material layer 150 a on the first electrodes 121is patterned to expose the first electrode 121.

In FIG. 8D, a second photo mask PM2 is disposed over the fillingmaterial layer 150 a. The second photo mask PM2 has a mask patterncorresponding to the second insulating layer 117 between the firstelectrodes 121.

In FIG. 8E, the filling material layer 150 a and the second insulatinglayer 117 are patterned to form the sixth trench T. Since thephotoresist pattern covers the first electrodes 121, the firstelectrodes 121 are protected by the photoresist pattern while thefilling material layer 150 a and the second insulating layer 117 arepatterned. In addition, a further optimized etching material may be usedfor the step of etching the second insulating layer 117. The etchingmaterial for patterning the filling material layer 150 a on the firstelectrode 121 may be different from the etching material for patterningthe filling material layer 150 a on the second insulating layer 117.Since the second insulating layer 117 and the planarizing layer 150 formthe sixth trench T together, a lower edge of the planarizing layer 150may coincide with an upper edge of the sixth trench T in the secondinsulating layer 117. The planarizing layer 150 and the secondinsulating layer 117 may include the sixth trench T commonly.

FIGS. 9A and 9B are cross-sectional views showing a method offabricating an organic light emitting display device according to afourth embodiment of the present disclosure. FIGS. 9A and 9B correspondto a line I-I′ of FIG. 1.

Steps of forming the transistors 111, the first and second metal layers114 a and 115 a, the first electrodes 121 and the filling material layer150 a of the fourth embodiment are the same as the steps of FIGS. 5A to5D of the first embodiment. A step of patterning the filling materiallayer 150 a on the first electrodes 121 of the fourth embodiment is thesame as the step of FIG. 8B of the third embodiment.

In FIG. 9A, a photo mask PM is disposed over the filling material layer150 a. The photo mask PM may have a mask pattern corresponding to thesecond insulating layer 117 between the first electrodes 121. The maskpattern may have a width smaller than a gap distance between the secondregions A2 of the planarizing layer 150 covering the side surface of thefirst electrodes 121.

In FIG. 9B, the planarizing layer 150 and the second insulating layer117 may be patterned so that the planarizing layer 150 can have thethird region A3 contacting the second insulating layer 117 and connectedto the second region A2. Since an influence due to the process deviationis reduced as compared with the third embodiment of FIGS. 8A to 8D, thedefective proportion is further reduced. In addition, since the sixthtrench has a uniform width, the step coverage of the organic lightemitting layer 130 and the second electrode 140 is effectively adjustedin subsequent processes. Since the second insulating layer 117 and theplanarizing layer 150 form the sixth trench together, a lower edge ofthe planarizing layer 150 may coincide with an upper edge of the sixthtrench T in the second insulating layer 117. The planarizing layer 150and the second insulating layer 117 may include the sixth trench Tcommonly.

FIG. 10 is photographs showing experimental results of the sixth trenchof an organic light emitting display device according to one of first tofourth embodiments of the present disclosure.

In FIG. 10, the sixth trench T in the second insulating layer 117 andthe planarizing layer 150 may have widths of about 0.19 μm, about 0.17μm and about 0.15 μm. When the sixth trench has a width of about 0.19μm, the organic light emitting layer 130 and the second electrode 140may be formed in the sixth trench T and the second electrode 140(cathode) may be cut. As a result, the second electrode 140 may be openby sub-pixel to have a relatively high resistance, and the organic lightemitting display device may not be driven due to a position deviation.When the sixth trench has a width of about 0.17 μm to about 0.15 μm, theorganic light emitting layer 130 is partially cut such that a portion ofthe organic light emitting layer 130 and the second electrode 140contact each other. As a result, deterioration due to the sixth trenchhaving a width of about 0.19 μm is prevented.

FIG. 11 is a graph showing experimental results of the sixth trench ofan organic light emitting display device according to one of first tofourth embodiments of the present disclosure.

In FIG. 11, the sixth trench T in the second insulating layer 117 andthe planarizing layer 150 may have depths of about 0.3 μm, about 0.4 μmand about 0.5 μm. When the sixth trench T has a depth smaller than about0.5 μm, a current increases at a voltage smaller than about 0V. Althoughthe diode of the organic light emitting layer 130 should be turned offat a voltage smaller than about 0V, the diode of the organic lightemitting layer 130 is turned on due to a leakage current through theside surface. The leakage current may be prevented by cutting theorganic light emitting layer 130 for the sixth trench T having a depthgreater than about 0.5 μm. Since the resistance of the organic lightemitting layer 130 increases by forming at least one of a stack and acharge generating layer of the organic light emitting layer 130, aninfluence on an adjacent pixel due to a leakage current through theorganic light emitting layer 130 may be minimized. As a result, it ispreferable for the sixth trench has a depth greater than about 0.5 μm.

FIG. 12 is a graph showing simulation results of the sixth trench of anorganic light emitting display device according to one of first tofourth embodiments of the present disclosure.

In FIG. 12, the sixth trench T in the second insulating layer 117 andthe planarizing layer 150 may have depths of about 0.3 μm, about 0.5 μmand about 1.0 μm. While the second electrode 140 of bar is continuouslyformed on the sixth trench T of depths of about 0.3 μm and about 0.5 μm,the second electrode 140 of bar is cut on the sixth trench T of a depthof about 1.0 μm. When the second electrode 140 is cut, the resistance ofthe second electrode 140 increases as in the experiments of the sixthtrench T of various widths, and the organic light emitting displaydevice may not be driven due to a position deviation. As a result, it ispreferable for the sixth trench has a depth equal to or smaller thanabout 1.0 μm.

FIG. 13 is a plan view showing an organic light emitting display deviceaccording to one of first to fourth embodiments of the presentdisclosure.

In FIG. 13, the sixth trench T may be formed at one side between thefirst electrodes 121 or may be formed at four sides of each of the firstelectrodes 121. When each of the first electrodes 121 has a shape otherthan a rectangular shape, the sixth trench T may be formed at all sidesof each of the first electrodes 121.

FIGS. 14A and 14B are a perspective view and a plan view showing a headmounted display including an organic light emitting display deviceaccording to one of first to fourth embodiments of the presentdisclosure.

In FIGS. 14A and 14B, a head mounted display HMD including an organiclight emitting display device includes a display case 10, a left eyelens 20 a, a right eye lens 20 b and a head band 30.

The display case 10 accommodates a display device and provides an imageof the display device to the left eye lens 20 a and the right eye lens20 b. The display device may be an organic light emitting display (OLED)device according to one of first to fourth embodiments of the presentdisclosure.

The display case 10 may be formed to provide the same image to the lefteye lens 20 a and the right eye lens 20 b. Alternatively, display case10 may be formed to provide a left eye image and a right eye image tothe left eye lens 20 a and the right eye lens 20 b, respectively. Thehead mounted display HMD of FIGS. 14A and 14B may be applied to avirtual reality (VR) device.

The head band 30 may be fixed to the display case 10. Although the headband 30 is formed to wrap an upper surface and a side surface of a headof a user in FIG. 14A, the shape of the head band 30 is not limitedthereto. The head band 30 is used for fixing the head mounted displayHMD to a head of a user. The head band 30 may have a glass shape or ahelmet shape in another embodiment.

FIG. 15 is a plan view showing a head mounted display including anorganic light emitting display device according to one of first tofourth embodiments of the present disclosure.

In FIG. 15, a head mounted display HMD includes a display case 10, aleft eye lens 20 a, a right eye lens 20 b, a left eye organic lightemitting display (OLED) device 11, a right eye organic light emittingdisplay (OLED) device 12 and a head band 30. The left eye OLED device 11and the right eye OLED device 12 may be disposed in front of the lefteye lens 20 a and the right eye lens 20 b, respectively, in the displaycase 10. The left eye OLED device 11 and the right eye OLED device 12may display a left eye image and a right eye image, respectively. Theleft eye image displayed by the left eye OLED device 11 is transmittedto a left eye LE of a user through the left eye lens 20 a, and the righteye image displayed by the right eye OLED device 12 is transmitted to aright eye RE of a user through the right eye lens 20 b.

A magnified lens may be further disposed between left eye lens 20 a andthe left eye OLED device 11 and between the right eye lens 20 b and theright eye OLED device 12. The left and right image displayed by the lefteye OLED device 11 and the right eye OLED device 12 may be magnified andtransmitted to the user. The HMD of FIG. 15 may be applied to anaugmented reality (AR) device.

FIG. 16 is a cross-sectional view showing a head mounted displayincluding an organic light emitting display device according to one offirst to fourth embodiments of the present disclosure.

In FIG. 16, a head mounted display includes a display case 10, a lefteye lens 20 a, a right eye lens (not shown), a reflecting plate 13 andan organic light emitting display (OLED) device 14. The OLED device 14displays an image toward the reflecting plate 13, and the reflectingplate 13 reflects the image of the OLED device 14 toward the left eyelens 20 a and the right eye lens. As a result, the image of the OLEDdevice 14 is transmitted to a left eye LE of a user through the left eyelens 20 a and a right eye of a user through the right eye lens. When ahalf mirror is used as the reflecting plate 13, the display case 10 mayhave a thin profile.

In addition, a magnified lens may be further disposed between the lefteye lens 20 a and the reflecting plate 13 and between the right eye lensand the reflecting plate 13. The image of the OLED device 14 may bemagnified and transmitted to the user.

Consequently, in an organic light emitting display device according toan embodiment of the present disclosure, since a planarizing layer isformed between first electrodes to fill a step difference of aninsulating layer and the first electrode, a shortage of the firstelectrode and a charge generating layer or a second electrode at a stepdifference area between the insulating layer and the first electrode isprevented. Since the planarizing layer partially covers a top surface ofthe first electrode, generation of a strong electric field between thefirst and second electrodes is prevented and deterioration of an organiclight emitting layer is prevented. A shortage of the first electrode andthe organic light emitting layer is prevented.

Since a trench is formed in the planarizing layer, a path of a leakagecurrent between adjacent pixels through the organic light emitting layermay be elongated as compared with an OLED device without a trench. Sincethe planarizing layer is formed to have a relatively great width in aregion where the planarizing layer and the insulating layer contact, awidth of the trench in the insulating layer may be adjusted. Since athickness of the organic light emitting layer on a sidewall of thetrench is smaller than a thickness of the organic light emitting layeron a bottom of the trench, a resistance of the organic light emittinglayer may increase and an influence on an adjacent pixel due to aleakage current through the organic light emitting layer may beminimized. In addition, since at least one of a stack and a chargegenerating layer of the organic light emitting layer is formed to haveat least one cut portion at a position where the sidewall surface andthe bottom surface of the trench meet, a resistance of the organic lightemitting layer may increase and an influence on an adjacent pixel due toa leakage current through the organic light emitting layer may beminimized.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in an organic light emittingdisplay device, a head mounted display including the same and a methodof fabricating the same of the present disclosure without departing fromthe spirit or scope of the disclosure. Thus, it is intended that thepresent disclosure covers the modifications and variations of theseaspects provided they come within the scope of the appended claims andtheir equivalents.

What is claimed is:
 1. An organic light emitting display device,comprising: an insulating layer; first electrodes disposed on theinsulating layer and spaced from each other by a gap; a planarizinglayer on the first electrodes; an organic light emitting layer on thefirst electrodes; and a second electrode on the organic light emittinglayer, wherein the insulating layer includes a trench in the gap betweenthe first electrodes, wherein the organic light emitting layer includesa first stack on the first electrodes, a charge generating layer on thefirst stack, and a second stack on the charge generating layer, whereineach of the first and second stacks includes a hole transporting layer,at least one emitting material layer and an electron transporting layer,wherein the first stack has a discontinuous portion in the trench and atleast one of the layers of the second stack extends continuously acrossthe trench, and wherein an outer side surface of the planarizing layercoincides with an inner side surface of the trench.
 2. The organic lightemitting display device of claim 1, wherein the charge generating layerhas a discontinuous portion in the trench.
 3. The organic light emittingdisplay device of claim 1, wherein a gap distance between the firstelectrodes is equal to or smaller than 0.7 μm.
 4. The organic lightemitting display device of claim 1, wherein a width of the first trenchis equal to or smaller than 0.17 μm.
 5. The organic light emittingdisplay device of claim 1, wherein a depth of the first trench is equalto or greater than 0.5 μm and equal to or smaller than 1.0 μm.
 6. Theorganic light emitting display device of claim 1, wherein theplanarizing layer includes a first region covering a portion of a topsurface of the first electrodes.
 7. The organic light emitting displaydevice of claim 6, wherein a width of the first region of theplanarizing layer is equal to or greater than 0.1 μm.
 8. The organiclight emitting display device of claim 1, wherein the planarizing layerincludes a second region covering a side surface of the first electrodesand a third region contacting the insulating layer and connected to thesecond region.
 9. The organic light emitting display device of claim 8,wherein a width of the third region is greater than a width of thesecond region.
 10. The organic light emitting display device of claim 1,wherein the first stack has a cut portion over the first trench in theinsulating layer.
 11. The organic light emitting display device of claim1, wherein the charge generating layer has a cut portion over the firsttrench in the insulating layer.
 12. A head mounted display, comprising:a display case; a left eye lens and a right eye lens in the displaycase; at least one organic light emitting display device providing atleast one image to the left eye lens and the right eye lens; and a headband connected to the display case, wherein the at least one organiclight emitting display device comprises: an insulating layer; firstelectrodes disposed on the insulating layer and spaced from each otherby a gap; a planarizing layer on the first electrodes; an organic lightemitting layer on the first electrodes; and a second electrode on theorganic light emitting layer, wherein the insulating layer includes atrench in the gap between the first electrodes, wherein the organiclight emitting layer includes a first stack on the first electrodes, acharge generating layer on the first stack, and a second stack on thecharge generating layer, wherein each of the first and second stacksincludes a hole transporting layer, at least one emitting material layerand an electron transporting layer, wherein the first stack has adiscontinuous portion in the trench and at least one of the layers ofthe second stack extends continuously across the trench, and wherein anouter side surface of the planarizing layer coincides with an inner sidesurface of the trench.
 13. A method of fabricating an organic lightemitting display device, comprising: forming an insulating layer on asubstrate; forming first electrodes on the insulating layer, the firstelectrodes spaced from each other by a gap; forming a planarizing layeron the first electrodes; forming an organic light emitting layer on thefirst electrodes; and forming a second electrode on the organic lightemitting layer, wherein the insulating layer includes a trench in thegap between the first electrodes, wherein the organic light emittinglayer includes a first stack on the first electrodes, a chargegenerating layer on the first stack, and a second stack on the chargegenerating layer, wherein each of the first and second stacks includes ahole transporting layer, at least one emitting material layer and anelectron transporting layer, wherein the first stack has a discontinuousportion in the trench and at least one of the layers of the second stackextends continuously across the trench, and wherein an outer sidesurface of the planarizing layer coincides with an inner side surface ofthe trench.
 14. An organic light emitting display device, comprising: afirst sub-pixel including a first electrode of the first sub-pixelcovering an insulating layer of the first sub-pixel and a planarizinglayer of the first sub-pixel on the first electrode of the firstsub-pixel; a second sub-pixel including a first electrode of the secondsub-pixel covering an insulating layer of the second sub-pixel and aplanarizing layer of the second sub-pixel on the first electrode of thesecond sub-pixel; and a trench between the first sub-pixel and thesecond sub-pixel that extends down through at least part of aninsulating layer between the first sub-pixel and the second sub-pixel,wherein the insulating layer of the first sub-pixel, the insulatinglayer of the second sub-pixel, and the insulating layer between thefirst sub-pixel and the second sub-pixel are part of a same layer,wherein the organic light emitting layer includes a first stack on thefirst electrodes, a charge generating layer on the first stack, and asecond stack on the charge generating layer, wherein each of the firstand second stacks includes a hole transporting layer, at least oneemitting material layer and an electron transporting layer, wherein thefirst stack has a discontinuous portion in the trench and at least oneof the layers of the second stack extends continuously across thetrench, and wherein an outer side surface of the planarizing layer ofthe first sub-pixel coincides with an inner side surface of the trench,and an outer side surface of the planarizing layer of the secondsub-pixel coincides with another inner side surface of the trench. 15.The organic light emitting display device of claim 14, furthercomprising an organic light emitting layer including two or more layersin the trench.
 16. The organic light emitting display device of claim14, wherein each of the first sub-pixel and the second sub-pixelincludes a planarization layer covering an edge of the first electrodeof the sub-pixel.